Platelet kinetics after slow versus standard transfusions: a pilot study

Evaluation and management of platelet transfusion refractoriness

Platelet transfusion refractoriness (PTR), in which platelet counts do not increase after transfusion, occurs in many patients receiving platelet transfusions. PTR is a clinical condition that can harm patients. The causes of PTR can be divided into two types: immune and non-immune. Most cases of PTR are non-immune. Among immune causes, the most common is human leukocyte antigen (HLA) class I molecules. PTR caused by anti-HLA antibodies is usually managed by transfusing HLA-matched platelets. Therefore, it is important, especially for hemato-oncologists who frequently perform transfusion, to accurately diagnose whether the cause of platelet transfusion failure is alloimmune or non-immunological when determining the treatment direction for the patient. In this review, we discuss the definitions, causes, countermeasures, and prevention methods of PTR.

Preoperative platelet transfusions: A retrospective review of pediatric patients with thrombocytopenia, 2011-2016

BACKGROUND

Thrombocytopenia is a common perioperative clinical problem and preoperative platelet transfusion prior to surgery is standard practice. Recent platelet trials and literature reviews have found no association between platelet count and bleeding incidence except when platelet count is extremely low. Our aim was to evaluate the bleeding risk and the overall platelet transfusion management among pediatric patients with severe thrombocytopenia based on whether they were preoperatively transfused versus transfused at time of incision.

METHODS

This is a retrospective analysis of pediatric patients with a platelet count ≤50 × 10⁹/L in the 12 h prior to surgery at a single tertiary pediatric hospital from 2011 to 2016. Eligible patients were ≤21 years old. Patients with necrotizing enterocolitis and neonates were excluded. The primary outcome was postoperative bleeding complications. Additional outcomes were preoperative platelet change and weight adjusted transfusion volumes.

RESULTS

A total of 37 patients were included in this analysis of which 29 (78%) received preoperative platelet transfusions within 12 h prior to surgery. No postoperative bleeding complications occurred 30 days after operation, regardless of preoperative transfusion status. There was no significant difference in platelet change by preoperative transfusion status and preoperative transfusion volume was a poor predictor of change in preoperative platelet count (crude: r²=0.19, age/gender adjusted: r²=0.48).

CONCLUSION

Patients transfused at time of surgical procedure did not have an increased risk of bleeding over those preoperatively transfused. This finding is in agreement with previous studies in adult populations, supporting the safety of deferring platelet transfusions until the time of incision for thrombocytopenic pediatric surgical patients.

LEVEL OF EVIDENCE

III.

A systematic literature review on the use of platelet transfusions in patients with thrombocytopenia

Objective: Investigate globally, current treatment patterns, benefit-risk assessments, humanistic, societal and economic burden of platelet transfusion (PT). Methods: Publications from 1998 to June 27, 2018 were identified, based on databases searches including MEDLINE®; Embase and Cochrane Database of Systematic Reviews. Data from studies meeting pre-specified criteria were extracted and validated by independent reviewers. Data were obtained for efficacy and safety from randomized controlled trials (RCTs); data for epidemiology, treatment patterns, effectiveness, safety, humanistic and societal burden from real-world evidence (RWE) studies; and economic data from both. Results: A total of 3425 abstracts, 194 publications (190 studies) were included. PT use varied widely, from 0%-100% of TCP patients; 1.7%-24.5% in large studies (>1000 patients). Most were used prophylactically rather than therapeutically. 5 of 43 RCTs compared prophylactic PT with no intervention, with mixed results. In RWE studies PT generally increased platelet count (PC). This increase varied by patient characteristics and hence did not always translate into a clinically significant reduction in bleeding risk. Safety concerns included infection risk, alloimmunization and refractoriness with associated cost burden. Discussion: In RCTs and RWE studies there was significant heterogeneity in study design and outcome measures. In RWE studies, patients receiving PT may have been at higher risk than those not receiving PT creating potential bias. There were limited data on humanistic and societal burden. Conclusion: Although PTs are used widely for increasing PC in TCP, it is important to understand the limitations of PTs, and to explore the use of alternative treatment options where available.

Extended Small-Dose Platelet Transfusions in Multitransfused Hemato-Oncological Patients: A Single-Center Experience

BACKGROUND

Refractoriness to platelet transfusion, prevalent among 15-20% of hemato-oncological patients, is associated with multitransfusions and inferior outcomes. We evaluated the effectiveness of extended slow-dose transfusion (ESDT) in increasing platelet increments in multitransfused patients.

METHODS

Patients treated after the implementation of ESDT were compared with historical controls treated with standard single-donor platelet (SDP) transfusions. Cohorts of early and late recipients were assembled for comparison, i.e. the 8th or 9th and 11th platelet unit per patient, respectively. Patients in the ESDT group received transfusions equal to half an SDP unit, administered over 4 h. Effectiveness was defined as a higher corrected count increment (CCI) at 1, 12, and 24 h after transfusion.

RESULTS

In the early-recipients cohort, 24-h-posttransfusion increments were available for 29 ESDT patients and 6 standard patients, and did not differ significantly between the groups (p = 0.078). The 24-h-posttransfusion increment was available for 20 ESDT patients and 7 standard patients in the late-recipients cohort. The CCI was significantly higher in the ESDT group (p = 0.042). ABO compatibility improved the CCI (p = 0.01).

CONCLUSIONS

ESDT demonstrated slightly higher increments at 24 h after transfusion in late recipients, suggesting this could be a cost-effective approach for the treatment of thrombocytopenic multitransfused hemato-oncological patients.